This invention generally concerns a device having a sound-absorbing shape for reducing atmospherically transmitted noise, and particularly one of the type comprising at least two substantially cup-shaped chambers that are arranged adjacent to one another in the direction of the vibrations that are introduced into the device. In devices of this type, the chambers delimit a shared cavity, hermetically sealed with respect to the environment, that is configured as a pneumatic spring.
A shaped device of this kind is known from German Patent 34 12 432. The sound-absorbing component of this reference is designed as a Helmholtz resonator, in which partial spaces are enclosed by cup elements joined to one another via a neck-shaped opening in the bottom of the inner cup element. To improve sound absorption, provision is made for the bottom of the inner cup element to be made of a plastic film, the remaining parts of the shaped component being made of metallic material, in particular a metal foil. Sound attenuators constructed according to the German patent have proven to be less than satisfactory in terms of their cost and production engineering. The cup elements must each be generated separately from one another and subsequently assembled to one another. Problems are encountered in tuning the largely metallic cup elements to the vibration being isolated.
There remains a need to further develop a sound attenuator that can be manufactured more easily and cost-effectively, and that provides improved absorption of atmospherically transmitted sound across a broader frequency range.